UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934

(Amendment No.  )*

Cogent Biosciences, Inc.

(Name of Issuer)

Common Stock, $0.001 par value

(Title of Class of Securities)

19240Q 201

(CUSIP Number)

June 28, 2021

(Date of Event Which Requires Filing of This Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

☒   Rule 13d-1(b)

☐   Rule 13d-1(c)

☐   Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

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CUSIP No. 19240Q 201
1	NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) TCG Crossover Management, LLC
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (see instructions)	(a)o (b)o
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware, United States

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:	5	SOLE VOTING POWER 2,009,988
	6	SHARED VOTING POWER 0
	7	SOLE DISPOSITIVE POWER 2,009,988
	8	SHARED DISPOSITIVE POWER 0

9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,009,988
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (see instructions) o
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 5.2%
12	TYPE OF REPORTING PERSON (see instructions) IA

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Item 1(a).	Name of Issuer:
	Cogent Biosciences, Inc.
Item 1(b).	Address of Issuer’s Principal Executive Offices:
	200 Cambridge Park Drive, Suite 2500 Cambridge, Massachusetts 02140
Item 2(a).	Name of Person Filing:
	TCG Crossover Management, LLC
Item 2(b).	Address of Principal Business Office or, if none, Residence:
	228 Hamilton Avenue, 3rd Floor Palo Alto, California United States 94301
Item 2(c).	Citizenship:
	The Investment Manager is a Delaware limited liability company.
Item 2(d).	Title of Class of Securities:
	Common Stock, $0.001 par value
Item 2(e).	CUSIP Number: 19240Q 201

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Item 3.	If this Statement is filed pursuant to 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
	(a)	o	Broker or dealer registered under Section 15 of the Act;
	(b)	o	Bank as defined in Section 3(a)(6) of the Act;
	(c)	o	Insurance company as defined in Section 3(a)(19) of the Act;
	(d)	o	Investment company registered under Section 8 of the Investment Company Act of 1940;
	(e)	x	An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);
	(f)	o	An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F);
	(g)	o	A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G);
	(h)	o	A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
	(i)	o	A church plan that is excluded from the definition of an investment company under Section 3(c)(14) of the Investment Company Act of 1940;
	(j)	o	A non-U.S. institution in accordance with Rule 240.13d-1(b)(1)(ii)(J);
	(k)	o	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K). If filing as a non-U.S. institution in accordance with Rule 240.13d-1(b)(1)(ii)(J), please specify the type of institution:

Item 4.	Ownership.
	Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1. TCG Crossover Management, LLC
	(a)	Amount Beneficially Owned:		2,009,988
	(b)	Percent of Class:		5.2%
	(c)	Number of shares as to which such person has:
		(i)	sole power to vote or to direct the vote:	2,009,988
		(ii)	shared power to vote or to direct the vote:	0
		(iii)	sole power to dispose or to direct the disposition of:	2,009,988
		(iv)	shared power to dispose or to direct the disposition of:	0

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Item 5.	Ownership of Five Percent or Less of a Class.
	If this statement is being filed to report the fact that as of the date hereof, the Reporting Persons have ceased to be the beneficial owner of more than five percent of the class of securities, check the following o.
Item 6.	Ownership of More than Five Percent on Behalf of Another Person.
	Not applicable.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company.
	Not applicable.
Item 8.	Identification and Classification of Members of the Group.
	Not applicable.
Item 9.	Notice of Dissolution of Group.
	Not applicable.
Item 10.	Certification.
	By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of and do not have the effect of changing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having such purpose or effect for the time being.

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SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

July 8, 2021

Date

/s/ Jaime Felix

Signature

Chief Compliance Officer

Name/Title

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